21930832 has 60 divisors (see below), whose sum is σ = 53942976. Its totient is φ = 8541120.

The previous prime is 21930809. The next prime is 21930851. The reversal of 21930832 is 23803912.

It is a super-2 number, since 2×21930832² = 961922784424448, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 21930832.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7353 + ... + 9895.

Almost surely, 2^21930832 is an apocalyptic number.

21930832 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21930832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26971488).

21930832 is an abundant number, since it is smaller than the sum of its proper divisors (32012144).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21930832 is a wasteful number, since it uses less digits than its factorization.

21930832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2576 (or 2563 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21930832 is about 4683.0366216804. The cubic root of 21930832 is about 279.9099710559.

Subtracting 21930832 from its reverse (23803912), we obtain a triangular number (1873080 = T₁₉₃₅).

The spelling of 21930832 in words is "twenty-one million, nine hundred thirty thousand, eight hundred thirty-two".